Rockwell Automation 1756-HYD02 ControlLogix Hydraulic Servo Module - Manual (Page 71)

Publication 1756-UM525A-EN-P - June 2003 71
Using the 1756-HYD02 Module Features Chapter 4
Position Error Tolerance Specifies how much position error the axis loop tolerates before issuing a position error fault. This value is
interpreted as a +/- quantity.
For example, setting Position Error Tolerance to 0.75 position units means that a position error fault will be
generated whenever the position error of the axis is greater than 0.75 or less than -0.75 position units.
This value is set to twice the following error at maximum speed based on the measured response of the
axis, during the autotuning process. In most applications, this value provides reasonable protection in case
of an axis fault or stall condition without nuisance faults during normal operation. If you need to change the
calculated position error tolerance value, the recommended setting is 120% to 150% of the position error
while the axis is running at its maximum speed.
Position Lock Tolerance Specifies the maximum position error the hydraulic module accepts to indicate the Position Lock status bit is
set. This is useful in determining when the desired end position is reached for position moves. This value is
interpreted as a +/- quantity.
For example, specifying a lock tolerance of 0.01 provides a minimum positioning accuracy of +/- 0.01
position units.
Output Limit Provides a method of limiting the maximum analog output voltage of a physical axis to a specified level. The
analog output for the axis as a function of position loop error, both with and without analog output limiting.
The analog output limit may be used if the valve cannot accept the full +/-10V range of the analog output. In
this case, the analog output limit value effectively limits the maximum command sent to the valve. For
example, if the valve can only accept command signals up to +/-7.5V, set the analog output limit value to
7.5V.
Manual Adjust This button accesses the Limits tab of the Manual Tune dialog for online editing.
The Manual Tune button is disabled when RSLogix 5000 is in Wizard mode, and when you have not yet
saved or applied your offline edits to the above parameters.
Feature: Definition: